Prior artisans have attempted to incorporate metal layers or metal filler particles in golf balls to alter the physical characteristics and performance of the balls. For example, U.S. Pat. No. 3,031,194 to Strayer is directed to the use of a spherical inner metal layer that is bonded or otherwise adhered to a resilient inner constituent within the ball. The ball utilizes a liquid filled core. U.S. Pat. No. 4,863,167 to Matsuki, et al. describes golf balls containing a gravity filler which may be formed from one or more metals disposed within a solid rubber-based core. U.S. Pat. Nos. 4,886,275 and 4,995,613, both to Walker, disclose golf balls having a dense metal-containing core. U.S. Pat. No. 4,943,055 to Corley is directed to a weighted warmup ball having a metal center.
Prior artisans have also described golf balls having one or more interior layers formed from a metal, and which feature a hollow center. Davis disclosed a golf ball comprising a spherical steel shell having a hollow air-filled center in U.S. Pat. No. 697,816. Kempshall received numerous patents directed to golf balls having metal inner layers and hollow interiors, such as U.S. Pat. Nos. 704,748; 704,838; 713,772; and 739,753. In U.S. Pat. Nos. 1,182,604 and 1,182,605, Wadsworth described golf balls utilizing concentric spherical shells formed from tempered steel. U.S. Pat. No. 1,568,514 to Lewis describes several embodiments for a golf ball, one of which utilizes multiple steel shells disposed within the ball, and which provide a hollow center for the ball.
As to the incorporation of glass or vitreous materials in golf balls, U.S. Pat. No. 985,741 to Harvey discloses the use of a glass shell. Other artisans described incorporating glass microspheres within a golf ball such as in U.S. Pat. No. 4,085,937 to Schenk.
In contrast, the use of polymeric materials in intermediate layers within a golf ball, is more popular than, for instance, the use of glass or other vitreous material. Kempshall disclosed the use of an interior coating layer of plastic in U.S. Pat. Nos. 696,887 and 701,741. Kempshall further described incorporating a fabric layer in conjunction with a plastic layer in U.S. Pat. Nos. 696,891 and 700,656. Numerous subsequent approaches were patented in which a plastic inner layer was incorporated in a golf ball. A thermoplastic outer core layer was disclosed in U.S. Pat. No. 3,534,965 to Harrison. Inner synthetic polymeric layers are noted in U.S. Pat. No. 4,431,193 to Nesbitt. An inner layer of thermoplastic material surrounding a core is described in U.S. Pat. No. 4,919,434 to Saito. An intermediate layer of an amide block polyether thermoplastic is disclosed in U.S. Pat. No. 5,253,871 to Viellaz. Golf balls with thermoplastic interior shell layers are described in U.S. Pat. No. 5,480,155 to Molitor, et al. Although satisfactory in many respects, these patents are not specifically directed to the use of reinforcement fibers or particles dispersed within a polymeric inner layer.
Prior artisans have attempted to incorporate various particles and filler materials into golf ball cores and intermediate layers. U.S. Pat. No 3,218,075 to Shakespeare discloses a core of fiberglass particles dispersed within an epoxy matrix. Similarly, U.S. Pat. No. 3,671,477 to Nesbitt discloses an epoxy-based composition containing a wide array of fillers. A rubber intermediate layer containing various metal fillers is noted in U.S. Pat. 4,863,167 to Matsuki, et al. Similarly, a rubber inner layer having filler materials is noted in U.S. Pat. No. 5,048,838 to Chikaraishi, et al. More recently, a golf ball with an inner layer of reinforced carbon graphite is disclosed in U.S. Pat. No. 5,273,286 to Sun.
In view of the ever increasing demands of the current golf industry, there exists a need for yet another improved golf ball design and construction. Specifically, there is a need for a golf ball that exhibits a high initial velocity or coefficient of restitution (COR), may be driven relatively long distances in regulation play, and which may be readily and inexpensively manufactured.
These and other objects and features of the invention will be apparent from the following summary and description of the invention, the drawings, and from the claims.